Various products formed of three-dimensional objects, such as gaskets which are integrated with a syringe plunger to form a seal between the plunger and the syringe barrel, have been proposed. Various surface-modified products have been offered as such three-dimensional objects, and they are used for a variety of applications. In commonly used conventional methods for surface modification, three-dimensional objects are individually modified.
Such methods have problems in that they have poor productivity, are unsuitable for mass production and difficult to put to practical use and that the processes for individual surface modification cost a lot and have poor economic efficiency, etc.